Theoretical modeling and analysis of a wireless Ultrasonic Power Transfer system

This paper proposes a new modeling method for analyzing an Ultrasonic Power Transfer (UPT) system. The acoustic excitation pressure generated by the piezoelectric transducer from an excitation voltage is modeled by considering the resonant properties of piezoelectric materials into the constitutive equations. Then a system-level equivalent circuit model is developed to analyze the system power transfer performance. The proposed models simplify the process to evaluate the system output characteristics. A prototype UPT system is simulated and constructed to verify the theoretical analysis through a case study. Experimental results demonstrate that 2W of electric power can be transferred across a 5mm thick aluminum plate to a resistive load at an efficiency of 60% using 28kHz piezoelectric transducers.